Apparatus for handling stands of pipe



Nov. 13, 1962 w. c. GUlER APPARATUS FOR HANDLING STANDS 0F PIPE 5 Sheets-Sheet 1 Filed May 25, 1959 /MZ8.%M

' ATTORNEY W. C. GUIER APPARATUS FOR HANDLING STANDS OF PIPE Nov. 13, 1962 5 Sheets-Sheet 5 Filed May 25, 1959 f E6, Ma

m W Y B & 0 '2 45 5 w W w W 7M4 All A TTORNE Y United States Patent 3,663,599 APPARATUS FOR HANDLING STANDS 0F PIPE William C. Guier, R0. Box 326, Tulsa 1, Okla. Filed May 25, 1959, Ser. No. 815,707 31 Claims. (Cl. 175200) This invention relates to an apparatus for handling stands of pipe as when making up and disconnecting long strings of pipe used in a bore hole for drilling, completing, conditioning, reconditioning, treating, plugging, and other operations that are carried out in exploration and recovery of petroleum and other fluids and minerals from substantial depths below the earths surface.

While the present invention is adapted to handling strings of pipe and the like used in connection with many operations relating to the making and servicing of bore holes, the invention will be described and illustrated for handling stands of drill pipe during drilling of -a bore hole, it being understood that operations in handling of the stands of pipe are the same even though the size and character of the pipe and couplings therefor may be different.

In present drilling practice, a drilling string consists of a plurality of sections or joints of drill pipe having a length (usually to 40 feet) convenient to its manufacture and transportation as well as its use in the drilling operation. Threaded tool joints are attached at either end so that the joints can be screwed together. The drilling string is run into and out of the bore hole in multiplejoint stands, each stand consisting of a number (usually two to four) of joints convenient for manipulation Within the height of the derrick of a drilling rig. When running the drilling string into the bore hole, the drilling, string is lowered by an elevator and is usually supported from the turntable by gripping the pipe with slips that wedge within the slip bowl of a master bushing which in turn seats within the rotating part of the turntable. Inserted in the slips are dies consisting of sharp teeth which are hardened so that the pressure from the wedging action causes them to bite into the pipe to assure a tight grip. After engagement of the slips, the elevator is released so that it can be lifted in the derrick for connection with the next stand of drill pipe and to support the stand while the lower end thereof is connected to the drilling string in the bore hole. After the connection is completed, the slips are released and the drilling string is again lowered into the bore hole until the added section is in position to be gripped by the slips to permit removal of the elevator for use thereof in connecting another stand of drill pipe. These operations are continued until sufficient stands have been added to make contact with the bottom of the bore hole, to continue with the drilling operation. The same procedure is followed When adding additional sections of pipe as the drilling progresses.

When it becomes necessary to pull the drilling string from the bore hole, the elevator is moved into position to connect with the upper end of the drilling string and to raise the drilling string in the derrick until the next lower stand of pipe is in position to be engaged by the slips to support the drilling string while the first of the stands is uncoupled therefrom and carried by the elevator into racking position Within the derrick. The elevator is then released and again lowered in the derrick to engage with the upper end of the following stand, to again raise the drilling string for support by the slips and permit uncoupling of the next stand of drill pipe. The operations are repeated until all of the drilling string has been removed from the bore hole and the stands of pipe racked within the derrick.

It is obvious that as the bore hole deepens and addi-' tional sections of drill pipe are added to maintain con- 3,0635% Patented Nov. 13, 1962 tact with the bottom of the bore hole, the weight of the drilling string increases with the addition of each stand for drill pipe, so that when it becomes necessary to pull the drill pipe, as when changing bits or for other reasons, the Weight of the drill pipe causes the slips to striate or score the pipe and cause deformation and bottlenecking (narrowing of the diameter in the slip contact area) thereof. The damage which results is doubly aggravated when setting up or wrenching the pipe while the slips hold the pipe from rotation after locking the rotary member of the turntable.

With the advent of deeper drilling, pipe manufacturers have been called upon to make pipe of greater tensile strength, and to supply this requirement the manufacturers have attempted to alloy and heat-treat the pipe so that it better withstands the tremendous weight, particularly when he pipe carries long lengths of heavy drill collars on the bottom of the drilling string. Consequently, when the slips are caused to grip such pipe, the teeth of the slips etch and score the high tensile metal and cause migrating cracks which can bring about complete failure and parting of the pipe. When this occurs, the result may become disastrous, and the only alternative is an expensive fishing job or complete abandonment of the bore hole.

The use of slips for gripping drill pipe has become such a problem in deep drilling that it has been proposed to eliminate the slips'entirely and to employ two conventional elevators which are alternately operated to support the drilling string from the turntable and to handle the pipe stand that is to be removed from or added to the drilling string. Two elevators adequately support the heavy drilling string from the annular shoulder of the tool joint and eliminate the hazards produced by the slips, but the manipulation thereof requires manual handling of the elevators to and away from the pipe, that is, the elevators must be bodily shifted, and the manual shifting of such heavy elevators is a slow and laborious task and is extremely dangerous to the personnel. In fact, the work is so hazardous that the use of dual elevators has never come into practical use.

Therefore, the principal object of the present invention is to eliminate gripping of the drill pipe by means of slips through the use of dual elevators, and to provide for automatic shifting of the elevators into and out of contact with the drill pipe under power.

It is also an object of the invention to utilize a hoisting mechanism having a single bail means which is automatically transferred from one elevator to the other under power. It is a further object to provide remote controls for the power mechanisms, so that no one of the crew on the derrick floor has occasion to approach the elevators except for releasing the elevator latches.

Other objects of the invention are to provide'simple and positive operating power means for shifting the elevators and to transfer the bail means from one to the other of the elevators; to provide the elevators with automatic safety mechanism for latching the bail means in engagement with the respective elevators and to effect automatically the release thereof; to provide the turntable with tracks on which the elevators are shifted from a rotary member of the turntable onto a stationary part of the track; to provide for contact of the elevators with the track to eifect release of safety latches which retain the bail means, and to guide the bail means from one elevator to engage the other; to provide a power operated lock for engaging and releasing the rotary member of the turntable from the stationary part; and to provide simple remote control mechanisms for the respective power mechanisms.

In accomplishing these and other objects ofthe inven tion as hereinafter pointed out, Ihave provided improved 3 7 structure and method for handling the drill pipe in the drilling of a bore hole, as illustrated in the accompanying drawings, wherein:

FIG. 1 is a fragmentary elevational view of a drilling rig equipped with a drill pipe handling apparatus embodying the features of the present invention.

FIG. 2 is a plan view of the turntable showing the rotary section of the track out of registery with the stationary track section, as when an elevator supported thereon and carrying the drilling string in the bore hole is rotated for disconnecting a stand of drill pipe.

FIG. 3 is a side elevational View of one of the elevators, partly in section, to better illustrate the safety latches for locking the elevator to the bails.

FIG. 4 is a similar section showing the elevator in support on the tracks of the rotary member of the turntable and the bails in released position, the tracks, turntable, bails and drill pipe being shown in dotted lines and the elevator in solid lines.

FIG. 5 is a plan view of the turntable and the power mechanism for shifting the elevators, with one elevator in position on the rotary member of the turntable and supporting the drilling string and the other elevator in position on the stationary portion of thetracks and with the gate of the elevator in open position.

FIG. 6 is a detail horizontal section on the line 6-6 of FIG. 9.

FIG. 7 is a side elevational view of the apparatus illustrated in FIG. 5, with parts being shown in section and brokenaway to better illustrate the construction.

FIG. 8 is a diagrammatic view of the elevator shifter and latch for the rotary member of the turntable, the bail transfer mechanism and the power cylinders therefor, with the fluid pressure supply lines and control valves therefor.

, FIG. 9 is a side elevationof the apparatus, with a portion of the turntable broken away and in section to better illustrate the elevator construction and the mounting of the pipe stripper. The figure also illustrates one of the elevators after it has been seated on the tracks of the rotary member of the turntable and just prior to release of the bails, with the bail transfer mechanism being shown ready fortransfer of the bails, the actual transfer being indicatedin dotted lines.

Referring more in detail to the drawings:

1 designates a drilling rigthat includes, in part, a derrick or mast 2 having a floor3. At the level of the floor isaturntable 4 and carried from the top 5 of the derrick is a hoisting tackle 6 for suspending a drilling string 7.

The drilling string 7 includes a plurality of joints of pipe 8, which are coupled together by tool joints 9. The tool joints 9vcomprise pin and box members 1% and 11. A box member 11 is rigidly attached to the upper end of a joint 8, and a pin member 10 is rigidly attached to the lower endof the joint 8. The members 1% and 11 making up a tool joint are of substantially heavy construction and provide annular shoulders 12 where they connect with the ends of the pipe section. The pinand box members of the tool joint thus provide threaded connec tions to facilitate coupling and uncoupling of the stands of pipe when running in and pulling out the drilling string from the bore hole.

The drilling string also includes a drill bit and the usual drilling collars in connection with the lower end thereof, and 8. Kelly' rod and swivel at the upper end, but these parts are not illustrated in the present drawings, since they constitute no part of the present invention and are well understood by those skilled in the drilling art.

The derrick or mast 2 may be of any standard type capable of handling heavy loads encountered in deep hole drilling. The derrick is of a height to handle the desired ing a plurality of sheaves 15 forming a part of the hoisting tackle 6. The hoisting tackle also includes a traveling block 16 having a plurality of sheaves corresponding with the sheaves of the crown block. The traveling block is suspended from the crown block by a hoisting cable 17 which is reeved over the respective sheaves and has one end reeled upon a hoisting drum of the draw works, not shown, to raise and lower the drilling string and to handle the stands of pipe.

The traveling block 16 may be of any conventional construction, but preferably includes a swivel 13 having laterally extending ears 19 projecting from opposite diametrical sides of the swivel to connect bails 28 and 21. The bails may be of a type having eyes 22 that pass over the ears 19 and are retained thereon by straps 23 (FIG. 1). The straps 23 have their upper ends pivotally connected with upper lugs 24. The lugs 24 are spaced above the ears 19 to provide passageways 25 for the eyes 22 of the bails when the straps 23 are disconnected from the ears i9 to permit attachment of the bails.

The turntable 4 includes a base 25 having an annular raceway 27 encircling a central opening 28 through the base. The base 26 also has a wall portion 29 that carries a shroud 30 for enclosing the gearing and rotary member 31 of the turntable. The rotary member 31 of the turntable has a barrel portion 32 extending down into the central opening 28 of the base and which carries an annular race 33 having support on antifriction members 34 that roll upon the raceway 27 (FIG. 9). The rotary member 31 has a platform portion 35 encircled by the shroud 30. Fixed to the rotary member below the platform portion 35 is a ring gear 36 that meshes with a. pinion gear (not shown) on a shaft 37 that is journaled in the side of the base and carries a sprocket 33 which is driven from the draw works by a chain 39, (FIG. 1). The barrel portion 32 of the rotary member 31 has an internal annular shoulder 40 to seat a master bushing 41 (H6. 9). The master bushing 41 is of the split type and ordinarily seats the slips above referred to and also a drive bushing for rotating the kelly rod. The kelly rod, drive bushing and slips are not shown, because they are not used when the present invention is in operation.

The structures thus far des ribed are conventional in drilling practice and may be obtained from the various manufacturers of drilling equipment.

In carrying out the present invention for handling drillpipe, dual elevators are employed and automatic means is provided for shifting the dual elevators and transferring the bails 20 and 21 from one elevator to the other by power mechanisms having remote controls, as now to be described.

The elevators are designated A and B and are manipulated to alternately support the drilling string by the turntable and to provide a traveling elevator by which the drilling string is raised and lowered through the turntable and to move the stands of pipe to and from racking position in the derrick.

The elevators A and B are especially constructed in accordance with the present inventionto provide for automatic connection and disconnection of the bails 2-8 and 21.

Each elevato is of the same construction, and cornpri'ses a generally semicircular body part 42 (FIGS. 3, 4, 5 and 6), adapted to engage over one side of the drill pipe and having its opposite side provided with an opening 43 (FIG. 5). Pivotally connected to the body part 4-2 at one side of the opening 43 by means of a hinge pin 44 (FIGS. 5, 6 and 7) is a gate 45 adapted to be secured to the body part 42 at the opposite side of the opening 43 by a latch 46. The gate 45, when closed and latched over a pipe, is substantially in the form of a collar to safely retain the pipe therein. The upper faces 47 of the gate 45 and body part &2 are in horizontal registry to seat against the shoulders 12 of one of the tool joints, as later to be described. Extending laterally from opposite ends of the body part on the respective sides of the opening 43 are arms 4% and 49. The arms 48 and 49 have upwardly and inwardly inclined slots 50 to form the upper portion of the arms into hooks 51 adapted to pass through eyes 52 on the lower ends of the bails 2t) and 21. The portions of the arms below the slots 5i are bifurcated or divided to provide spaced apart wings 53 (FIGS. 1, 7 and 9), the lower ends 54- of which are inclined upwardly toward the entrances to the slots so (FIGS. 3 and 4) to provide inclined seats 55 adapted to seat upon tracks 56 and 57 on the turntable, as later to be described.

=Pivotally mounted in the space between the wings 53 on transverse pins 58 are latches 59 (FIGS. 3 and 4). The latches 59 have keeper portions 60 that close the entrance ends of the slots 50, and have track engaging portions 61 that project below the inclined seating faces of the wings 53 when the keeper portions 69 close the slots 50, as shown in FIG. 3. The latches also have tail portions 62 that connect with one end of springs 63 having their opposite ends fixed to a part of the elevator, so that the springs retain the latches in the position shown in FIG, 3, t prevent disengagement of the eyes 52 of the bails 20 and 21 from the hooks 51-. The body part 42 of each elevator is provided on the side opposite the gate with a lug 64 having a horizontal bar portion 65 (FIGS. 5 and 7) adapted to be engaged by a gripper or catch of an elevator shifting means, later to be described.

The tracks 56 and 57 are arranged in parallel relation (FIGS. 2 and 5) on the respective sides of the drill pipe opening in the master bushing 41, and each track has a movable section 66 attached to a removable plate 67 car' ried on the platform portion 35 of the rotating part of the turntable, and a stationary section 68 offset laterally from the plate 67. The plate 67 has a square 67 (FIG. 9) fixed within the square of the master bushing and which seats upon a pipe stripper 69, which in turn seats upon an internal shoulder 70 of the master bushing 41, as best illustrated in FIG. 9. The stationary sections 68 of the tracks may be carried by a bracket 72 secured to the shroud of the turntable, as indicated in FIG. 9. The bracket 72 has lateral arm portions '73 and 74 attached to the base 26 of the turntable, as best shown in FIGS. 2 and 5. When the bracket 72 is attached to the turntable, the sections 68 of the tracks overhang the rotating platform of the rotary member of the turntable. The tracks, including the rotary and fixed portions thereof, have inwardly and downwardly beveled faces 75 corresponding to the lower inclined edges 54 of the wing portions of the elevator arms, as best shown in FIG. 4, whereby the elevator is adapted to seat thereon and be centered with respect to the turntable.

The plate 67 has a central opening 76 registering with the opening of the master bushing 41. The plate 67 is preferably a single unit, and to permit application thereof when the drill pipe is in the bore hole, the plate 67 has a slot 77 connected with the opening 76 and extending through the outer edge thereof, as shown in FIG. 2.

In order to latch the rotary part of the turntable to register the track sections, a latch plate 78 is reciprocable between the tracks of the fixed or stationary section 63 into engagement with the open end of the slot 77.

The bracket 71 also carries spaced apart vertical plates 79 and 8t) interconnected by transverse rods 81, 82 and 83 for mounting the power mechanisms therebetween (FIGS. 1 and 9). The plates 79 and 81) are so shaped that the transverse rod 81 is substantially in horizontal registry with the cross bar 65 on the elevators when an elevator is supported on the tracks.

Pivotally mounted on the rod 81 is one end of a power cylinder 84 and slideable in the opposite end of the cylin der is a piston rod 85 carrying a head 36 on a rider or slide 87 that is reciprocable upon the tracks 56 and 57, as shown in FIGS. 7 and 8, the runner having depending ferred from one elevator to the other.

6 ends 88 engaging over the outer sides of the tracks to keep thehead 86 in alignment with the axis of the cylinder 84. Carried by the head 66 and projecting therefrom in the direction of the turntable are spaced apart resilient arms 89 having hook shaped ends 91 to provide a catch adapted to engage over the bar portion 65 on the elevators when an elevator is to be shifted along the tracks, as later described. Pivotally mounted on the transverse rod 82 is a relatively shorter power cylinder 93 having a piston rod 94 that is connected by a clevis 95 with the latch plate or bar 78, whereby the latch plate 78 is moved into and out of holding engagement with the plate 67 on the rotary member of the turntable (FIGS. 8 and 9).

A power cylinder 96 is pivotally carried on the rod 83 and extend vertically upwardly at one side of the hori zontal cylinder 84. The power cylinder 96 also has a piston rod 97 slideable therein for actuating a mechanism for swinging the bails 20 and 21 from one elevator to the other, as now to be described.

Fixed to an upper portion of the derrick by a clevis 98 is a guide means that may be a single cable 99 depending within the derrick and which has its lower end 100 attached to the periphery of an eccentric means which in the illustration is a disk 101 that is fixed eccentrically to a transverse shaft 102 having its ends journaled in the plates '79 and so (FIG. 9).

The shaft 162 has a sprocket 103 fixed thereto and operating over the sprocket is a chain 104, one end of which is connected with the piston rod 97, while its opposite end depends from the sprocket and carries a counterweight 105 by which the chain 104 is kept in contact with the teeth of the sprocket, as shown in FIG; 9. Reciprocation of the piston rod 97 will rock the shaft 102 to swing the eccentric disk 101 and tension the cable 99 to draw the cable away from the center of the bore hole, and thereby swing the bails 2t) and 21 from engagement with an elevator seated upon the rotary section ofthe tracks to a position where they engage an elevator on the fixed section of the tracks, as later to be described.

In order to connect the bails with the cable 99 the cable carries a runner 196 in the form of a sleeve through which the cable extends (FIGS. 1 and 9). The runner 166 has an eye 167 which is connected with similar eyes 108 and 169 on links 119 and 111. The links 110 have eyes 112 at the opposite ends that are connected with the eyes 113 .and 114 on the bails 20 and 21. The links are interconnected by a spring 115 (FIG. 6), to draw the bails toward each other to retain them in guiding contact with outer sides of the tracks 56 and 57 when they are being trans- The links 116 and 111 are supported in substantially horizontal position by ties 116 having one end connected with the bails above the eyes 113 and 114 and the opposite ends connected with eyes 117 attached to the eyes 108.

It is obvious that two cables 99 may be used, in which case they would be suspended in the derrick in alignment with the bails 20 and 21, and each cable would have a runner 106 connected with a corresponding bail. In this case, two eccentric disks 101 would be fixed to the shaft for simultaneously tensioning the cables for swinging the bails. Also in this case the spring 115 would interconnect the runners.

The piston rods 85, 94 and 97 are caused to be operated remotely through a pressure fluid supply system, best i1lustrated in FIG. 8. The pressure fluid, for example, compressed air, is supplied through a conduit 118 having branches 119, 121 and connecting withfour-way valves 123 and 124 and a three-way valve 125, respectively. The valve 123 is connected by conduits 126 and 127 with the respective ends of the cylinder 93, whereby when the valve 123 is in one position, air is supplied to the rear end of the cylinder 93 and exhausted from the front end of the cylinder, to effect movement of the latch 78 in engagement with the plate 67, and when the valve 123 is moved to another position, the pressure fluid is supplied to the front end of the cylinder 93 and exhausted from the rear end, to effect retraction of the latch 78.

The valve 125 is connected by a conduit 123 with the upper end of the vertical cylinder 96, to draw the piston rod 97 downwardly and lift the counterweight P35 for rotating the eccentric disk 191 in one direction to tighten the cable 99 to shift the bail 2% and 21 away from the turntable. When the valve 125 is in its other position, the air is exhausted, whereupon the counterweight 1535 becomes effective to rotate the eccentric disk 1&1 in the opposite direction to produce slack in the cable 99, as later to be described.

The valve 124 is connected by conduits 129 and 13%) with the respective ends of the cylinder 84 for alternately admitting pressure fluid to one and the other ends of the cylinder 84 and exhaust pressure fluid from the opposite end of the cylinder, for reciprocating the spring catch 9t) for shifting an elevator on the tracks, as hereinafter described.

The plates 79 and 80 also carry a transverse bar 131 above the level of the spring catch d to provide a stop for an elevator when it is shifted onto the stationary tion of the tracks.

sec-

When the drilling rig has been set up as described equipped with a turntable and a dual elevator handling apparatus embodying the features of the present invert tion and drilling has been in progress to produce a bore hole and stands of drill pipe have been added to extend the length of the drilling string as required, and it becomes necessary to pull the drilling string to change the drill bit, the procedure is as follows:

The drilling string is lifted from off the bottom of the bore hole by the hoisting tackle 6 until the kelly lifts the drive bushing therefor out of the master bushing 41 and the first tool joint 9 appears above the turntable. The stripper 69 is seated on the shoulder 70 of the master bushing 41, and the plate 67 with the track section 66 thereon is placed on the rotary member 31 of the turntable with the square 67 thereof engaging in the square of the master bushing 41. An elevator, for example, the elevator A with the gate 45 thereof in open position is seated upon the stationary section 68 of the tracks 56 and 57 with the inclined seats 54 and 55 of the elevator resting upon the inclined faces 75 of the tracks, whereby the elevator A is aligned with respect to the center of the bore hole. The latch plate 78 is then shifted to engage the plate 67 and hold it from rotation to also look the rotary element of the turntable. This is effected by adjusting the valve 123 to supply pressure fluid to the cylinder 93 by way of the conduit 127. The lift of the drilling string is continued by the hoisting tackle until the lower shoulder of the tool joint which connects the kelly rod with the first stand of drill pipe comes above the top face of the elevator A. The elevator A is now shifted laterally along the tracks and under the bottom shoulder 12 of the tool joint. This is effected under power of the cylinder 84, which constitutes a transfer cylinder. The shift is effected by operating the three-way valve 124 to permit flow of pressure fluid to the rear end of the cylinder 84 through the conduit 130 and to discharge any pressure from the forward end of the cylinder 84 through the conduit 125. The pressure fluid acting within the rear end of the cylinder pushes the piston rod 85 forwardly to move the spring catch 90 against the cross bar '65 on the elevator A to push the elevator A from the stationary section '68 of the tracks onto the movable section 66. Since the elevator is of the automatic gate closing type, wherein a part 132 (FIG. on the gate engages the rear face of the pipe, continued movement 'of the elevator closes'and latches the gate auto matically. Upon closing and latching of the gate, the pipe is completely encircled by the levator. The drilling string is lowered by the hoisting tackle 6 to seat the shoulder 12 of the tool joint member 11 upon the upper face 47 of the elevator A, and since the elevator A is supported on the turntable, the entire weight of the drilling string is carried upon the elevator. The latch plate 78 may now be released. This is accomplished by manipulating the valve 123 so that pressure fluid is admitted to the forward end of the cylinder through the duct 126. With the kelly rod held from rotation by the usual tonging mechanism, not shown, the tool joint connecting the kelly rod is broken loose and freed from the drilling string that is supported by the elevator A. The kelly rod with the kelly rod drive bushing thereon is lifted by the swivel and moved to the side of the derrick, after which the bail of the swivel is disengaged from the hoisting tackle. If the bails 20 and 21 are not in connection with the traveling block 16, they are connected thereto. The elevator B is then picked up from the derrick floor by the hoisting tackle and brought thereby over the axial center of the drill pipe. Upon lowering of the elevator B, the runner 1% will slide on the cable 99 as the ele vator moves downwardly toward the turntable, but while the elevator is a considerable distance above the turntable, the valve 125 is operated to admit pressure fluid from the branch 125) to flow through the conduit 128 into the upper end of the power cylinder 96 for drawing the piston rod 97 downwardly and rotating the shaft 102 through the chain and sprocket connections 104 and 103. This movement of the shaft 102 rocks the eccentric 101 in a downward direction to tighten the cable 99, which causes the runner 166 to swing the elevator B on the cars 19, whereby the elevator B is seated upon the stationary section of the tracks, as indicated in dotted lines in FIG. 1. When the track-engaging ends 61 of the latches 59 engage the tracks, the latches '59 are caused to rock on the pins 53 and move the detent ends 6t thereof out of the downwardly inclined slots 50.

After seating of the elevator B, the downward movement of the traveling block is continued, so that the eyes 52 cf the bails slide out of the open ends of the slots 59 and pass to the outer sides of the tracks 56 and 57, as shown in dotted lines, FIG. 4. Upon release of pressure fluid from the upper end of the power cylinder 96 by reversing the valve 125 to exhaust position, the counterweight 105 is effective to rotate the eccentric 101 in a clockwise direction (FIG. 9) and produce slack in the cable 99, as shown in FIG. 9. This allows the bails t swing on the ears 19, with the eyes 52 guided by the outer sides of the tracks, into alignment with the arms 48 and 49 of the elevator A.

After the shift of the elevator A was completed, the spring catch was returned to its retracted position. This was effected by reversing flow of pressure fluid to the transfer cylinder 84.

The houisting tackle is then operated to lift the bails 20 and 21, whereupon the eyes 52 of the bails slide over the upper edges of the track and into the slots 50 of the elevator A, so that the hooks 51 thereof pass through the eyes 52 of the bails. Upon continued upward movement, the bails 2t} and 21 lift the elevator A and the drilling string carried therein upwardly within the derrick. As soon as the latches 59 are fre from the tracks 56 and 57, the springs 63 are effective to cause the latches to turn on the pins 58 and lead the detent ends 60 thereof into closing relation with the open ends of the slots 50, so that the eyes 52 of the bails cannot accidently disengage from the books of the elevator A during lift of the drilling string. The lift by the hoisting tackle is continued until the shoulder 12 of the tool joint connecting the next lower stand of pipe is in position above the rotary platform 67 of the turntable to accommodate the elevator B. As above stated, the drill pipe is pulled in as long stands as possible with the height of the derrick used, and in tall derricks and masts in treble or fourble stands, as this, of course, reduces the time required to pull the drilling string.

The platform plate 67 is again latched by means of the latch 78 and the elevator B is then shifted by the piston rod 85 of the transfer cylinder 84 in the manner as previously described. With the elevator B in position to support the drilling string, the stand carried by the elevator A is held by tongs, and the latch 78 is disengaged to allow the rotary member of the turntable to turn for spinning loose the stand of drill pipe. The freed stand of drill pipe is then moved to racking position in the derrick while contained in the elevator A. The derrickman on the fourble board 13 then unlatches the gate 45 to free the elevator A from the stand of drill pipe.

The elevator A with the gate open is again lowered by the hoisting tackle, during which time the cable 99' is tightened, to cause the elevator to land on the stationary section 68 of the tracks. As soon as the ends 61 of the latches engage the tracks, the latches 59 rock to release the bails 20 and 21 so that continued downward movement of the traveling block lowers the bails to cause the eyes 52 therof to slide out of the slots 50 and engage the outer sides of the tracks. The cable 99 is then slacked off so that the bails are free to swing along the tracks into registry with the hooks on the elevator B, so that upon lifting of the bails by the hoisting tackle, the eyes 52 of the bails fall into position to engage the hooks of the elevator B and lift the drilling string for removing and racking the next stand. The remaining stands of drill pipe are pulled and racked in like manner until the drill collars and bit have been removed from the bore hole.

After changing the bit, the stands of pipe are run into the bore hole in reverse order. After the bit has been lowered through the turntable 4 and the master bushing 41 is set in place, the drill collars are run with the slips in the usual manner and a stand of pipe is made up with the last drill collar carried by the slips. The partialiy made up drilling string is hoisted by the elevator A enough to remove the slips and place the platform plate 67 on the rotary part of the turntable. The partially made up drilling string is lowered in the bore hole until the elevator A is seated on the tracks. Seating of the elevator automatically actuates the latches 59, whereupon the eyes 52 of the bails 2i and 21 slide out or" the slots 50 to the sides of the track. The elevator B, with its door open, has been reposing on the stationary section of the tracks. The cable 99 is again tensioned by rocking the eccentric 101 as previously described. However, this time the freed bails are swung along the tracks to register with the arms 48 and 49 'of the elevator B to engage the eyes 52 with the hooks 51 thereof. Upon picking up the bails, continued movement of the bails picks up the empty elevator B with the gate 45 still'open. The elevator B is lifted in the derrick to a position Where the derrickman on the fourble board can close the elevator over the next stand of pipe. Upward movement of the elevator is continued until .the shoulder 12 of the tool joint at the upper end of the stand is engaged by the elevator. The elevator B then lifts the stand of pipe and carries it to a position where the pin member on the lower end of the stand engages the box member on the stand of pipe then supported by the elevator A on the turntable. With the turntable locked from rotation and the latch plate 78 engaged, the stand of pipe held by the hoisting tackle in the elevator B is spun into connection with the pipe held by the elevator A. The drilling string is then lifted by the elevator B to free the elevator A on the tracks. The latch on the gate 45 of the elevator A is released so that the gate may open. The valve 124 is then operated to admit pressure fluid to the rear end of the cylinder 84 and exhaust from the forward end, so as to project the spring catch 90 into position where the hooked ends 91 thereof engage over the cross bar 65 of the elevator A. The valve 124 is reversed, to exhaust pressure fluid from the rear end of the cylinder 84 and admit pressure fluid to the front end of the cylinder, to cause the spring catch to pull the elevator A along the tracks onto the stationary section thereof. When the elevator starts to move, the pipe causes the gate thereof to swing open. I

As soon as the elevator engages the stop bar 131, th hooked ends of the spring catch slip off the bar 165 to free the empty elevator A and leave it in place on the stationary section of the tracks. The hoisting tackle is then operated to lower the drilling string until the elevator B carried by the bails seats upon the section 66 of the tracks. As soon as the latches 59 engage the tracks, the latches swing out of position to free the bails and further downward movement of the bails causes them to slide out of the slots 51 and to engage the outer sides of the tracks. The Valve is then operated to admit pressure fluid into the upper end of the cylinder 96 to cause the eccentric 161 to tension the cable 99 to shift the bails into position for engaging the hooks of the empty elevator A that is seated on the stationary section 63 of the tracks. The elevator A is then lifted to a position where the derrickman on the fourble board can attach the elevator to another stand of drill pipe. The engaged stand is then brought into position and engaged with the stand supported by the elevator B on the turntable. The stand supported in the elevator A by the hoisting tackle is then spun up and tonged in the usual manner.

The remaining stands are engaged and connected with the drilling string in the bore hole in like manner until the bit is in drilling position on the bottom of the bore hole. The platform plate 67 is then removed, after which the kelly is connected with the drilling string in accordance with the usual method and the kelly drive bushing is seated within the master bushing to continue drilling operations.

It is to be noted that with the apparatus of the present invention all of the various operations of handling the stands of drill pipe are carried on continuously and that transfer of the elevators and movement of the bails of the single hoisting mechanism are under power, so that the drilling string may be run into and pulled from the bore hole with greater rapidity, thereby reducing the nondrilling time consumed in running in and pulling the drilling string. It is obvious that the two sections 66 and 68 of the track make up a support having seats at the respective ends thereof, one for the elevator which serves to support the drilling string and the other for supporting the empty elevator during transfer of the bails.

It is also obvious that with the apparatus described, the elevators are shifted under power through remote control, thereby eliminating hazards which result from present practices where dual elevators are employed.

While, as above stated, the invention is described and illustrated in handling the stands of drill pipe composing a drilling string, the procedure is the same for handling stands of pipe or the like used in other operations to be carried out in a bore hole.

What I claim and desire to secure by Letters Patent is:

:1. An apparatus for handling stands of drill pipe in a mast or derrick when connecting and disconnecting said stands in making up or pulling a drilling string employed in drilling a bore hole, said apparatus comprising a pair of elevators each having track engaging portions, an elevator support over -the bore hole including a track extending laterally of the bore hole to be engaged by said track engaging portions of the elevator for carrying one of the elevators thereon, a single hoisting apparatus for alternately lowering and raising the elevators to and from the support, and power means for alternately transferring one of the elevators along the track to and from contact with the drill pipe extending through the support and into the bore hole.

2. An apparatus for handling stands of drill pipe in a derrick when making up a string of drill pipe employed in drilling a bore hole, wherein said apparatus includes a platform member over the bore hole, a hoisting apparatus for raising and lowering stands of drill pipe through the platform member, dual elevators, bails suspended from the hoisting apparatus for connectionwith one of said elevators to raise and lower a stand of drill 'pipe to be connected with a string of drill pipe carried by the other elevator on the platform member, power means for shifting said other elevator from the platform member after connection of said stand of drill pipe with the string of drill pipe, means for automatically releasing the hails from said one elevator responsive to contact of said one elevator with a part on the platform member and to further lowering of the bails by the hoisting apparatus, and power means for transferring the hails from said one elevator to said other elevator for use in raising and lowering the next stand of drill pipe to be connected with the string of drill pipe in the bore hole.

3. An apparatus for handling stands of drill pipe in a derrick when making up a string of drill pipe employed in drilling a bore hole, wherein said apparatus includes a platform member over the bore hole, a hoisting apparatus for raising and lowering stands of drill pipe through the platform member, dual elevators, elevator supporting means laterally of the platform member, bails suspended from the hoisting apparatus for connection with one of said elevators to raise and lower a stand of drill pipe to be connected with a string of drill pipe carried by the other elevator positioned on the platform member, power means for shifting the said other elevator from the platform member to the lateral supporting means after said stand of drill pipe has been connected with the string of drill pipe, and power means for transferring the bails from the one elevator after said one elevator is seated upon the platform member to the said other elevator that is positioned upon said lateral supporting means, whereby the elevator on the lateral supporting means is next used in raising and lowering the next stand of drill pipe to be connected with the string of drill pipe in the bore hole.

4. An apparatus for handling stands of drill pipe as described in claim 3, wherein the bail transfer means and said power means are reversible for manipulation of the elevators in reverse relation for handling the stands of drill pipe when pulling the string of drill pipe from the bore hole. a

5. An apparatus for handling stands of pipe in a derrick when making up a string of pipe employed in a bore hole, wherein said apparatus includes a platform member having support over the bore hole, a hoisting apparatus for raising and lowering stands of pipe through the platform member, dual elevators, elevator supporting means laterally of the platform member, bails suspended from the hoisting apparatus forconnection with one of said elevators to raise and lower a stand of pipe to be connected with a string of pipe in the bore hole when the other elevator is positioned on the platform member and is supporting said string of pipe in the bore hole, power means for shifting said other elevator from the platform member to the lateral supporting means after said stand of pipe with the string of pipe has been connected, cable means suspended in the derrick, means connecting the bails with said cable means, and power means connected with said cable means for efiecting transfer of the hails from said one elevator on the platform member to the said other elevator on said lateral support whereby the elevator on the lateral support is used in raising and lowering the next stand of pipe to be connected with the string of pipe.

6. An apparatus for handling stands of pipe in a derrick when making up a string of pipe used in a bore hole, said apparatus including a hoisting tackle suspended from the top of the derrick, track means extending over the bore hole, a pair of bails connected with the hoisting tackle, a pair of elevators for engaging said stands of pipe and having track engaging portions, one of'said elevators being seatable with the track engaging portions thereof on the track means when the other elevator is carried by said hails from the hoisting tackle, power 12 actuated transfer means for shifting said one elevator along the track means to a position laterally of the bore hole, said other elevator being lowered by the hoisting tackle to seat the track engaging portion thereof upon the track means in the position previously occupied by said one elevator, and power actuated means connected with the bails for effecting shift of the bails from said other elevator to the said one elevator for lifting said one elevator from the track means by the hoisting tackle.

7. An apparatus as described in claim 6 for handling stands of pipe in a derrick, wherein the track means has bail guiding means for guiding the bails along the track means during shift thereof to said one elevator, and the elevators have means for guiding the bails into connection with said one elevator upon lifting of the bails by said hoisting tackle.

8. An apparatus for handling stands of drill pipe, including an elevator support, a hoist for raising and lowering stands of drill pipe through the elevator support, bail means connected with the hoist, a pair of elevators adapted for alternately supporting drill pipe from the elevator support and from said hoist, power means for shifting one elevator from the elevator support to a position laterally thereof, said other elevator with the drill pipe therein being adapted to be lowered into the elevator support, power means for transferring the bail means from the position of said other elevator to said one elevator that is in said lateral position thereof to connect the said one elevator with the hoist upon lifting of the bail means, and. control means for effecting actuation of the respective power means.

9. An apparatus for handling stands of pipe, including a hoist for raising and lowering stands of pipe through a platform member, bail means connected with the hoist, a pair of elevators adapted for alternately supporting pipe from the platform member and from said hoist, power means for shifting one elevator from the platform member to a position laterally of the platform, power means for transferring the bail means from the position of said other elevator to said one elevator to effect connection of the bail means with the said one elevator upon lifting of the bail means with the hoist, and control means for effecting actuation of the respective power means, said control means being operable for reversing movement of the power actuated means for alternately reversing shift of the elevators from said lateral position to the platform member and a corresponding reversal in transfer of the bail means.

10. An apparatus for handling stands of drill pipe, including a hoist for raising and lowering stands of drill pipe through a platform member, a pair of elevator bails having swing connection with the hoist, a pair of elevators adapted for alternately supporting drill pipe from the platform member and from said hoist, power means for shifting one elevator from the platform member to a position laterally of the platform member, said hoist being adapted to lower the other elevator with the drill pipe therein for support on the platform member, power means for swinging the hails from the position of said other elevator to the position of said one elevator to connect the said one elevator with the bails upon lifting of the bails by the hoist, and control means for effecting actuation of the respective power means.

11. An apparatus for handling stands of drill pipe, including a hoist for raising and lowering stands of drill pipe through the rotary element of a platform member, a pair of elevator bails having swing connection with the hoist, a pair of elevators adapted for alternately supporting drill pipe from the platform member and from said hoist, power means for shifting one elevator from the platform member to a position laterally of the platform member, power means for swinging the hails from the position of said other elevator to the position of said one elevator to connect the bails with the said one elevator upon lifting of the bails by the hoist, and control 13 means for effecting actuation of the respective power means, said control means being operable for effecting reverse movement of the power actuated means for re versing shift of the elevators from said lateral position onto the platform member and a corresponding reversal for transfer of the bails.

12. An apparatus for handling stands of drill pipe in a derrick of a rotary drilling rig which includes a hoisting tackle suspended from the top of the derrick and a turntable through which the drill pipe is raised and lowered into the bore hole or removed therefrom by the hoisting tackle, said apparatus including a track having a section extending laterally of the turntable and a section for mounting on the turntable, a pair of bails connected with the hoisting tackle, a pair of elevators for engaging said stands of drill pipe, one of said elevators being seatable on one of the sections of the track and the other elevator being carried by said bails, power actuated transfer means for shifting said one elevator along the track to the other section, a cable depending in the derrick alongside the hoisting tackle, a runner carried by the bails and slideable on the cable, power actuated means connected With the cable for tensioning the cable to effect shift of the bails to the said one elevator for lifting said one elevator by the hoisting tackle, means for supplying a pressure medium to the power mechanisms, and means remote from the power means for controlling flow 'of pressure medium to the power mechanisms.

13. An apparatus for handling stands of drill pipe in a derrick of a rotary drilling rig which includes a hoisting tackle suspended from the top of the derrick, a turntable through which the drill pipe is raised and lowered into the bore hole or removed therefrom by the hoisting tackle, said apparatus including a track having a section extending laterally of the turntable and a section for mounting on the turntable, a pair of bails connected with the hoisting tackle, a pair of elevators for engaging said stands of drill pipe, one of said elevators being seatable on one of the sections of the track and the other elevator being carried by said bails, power actuated transfer means for shifting said one elevator along the track to the other section, a cable depending in the derrick alongside the hoisting tackle, a runner carried by the bails and slideable on the cable, and power actuated means connected with the cable for tensioning the cable to effect shift of the bails to the said one elevator for lifting said one elevator by the hoisting tackle.

14. An apparatus for handling stands of drill pipe in a derrick of a rotary drilling rig which includes a hoisting tackle suspended from the top of the derrick, a turntable having a rotary part through which the drill pipe is raised and lowered into the bore hole or removed therefrom by the hoisting tackle, said apparatus including a track having a section extending laterally of the turn-table and a section for mounting on the rotary part of the turntable, a pair of bails connected with the hoisting tackle, a pair of elevators for alternately engaging said stands of drill pipe and supporting drill pipe from the turntable, power actuated transfer means for shifting said one elevator along the track to the other section, a latch for locking the rotary part of the turntable during shift of said elevator, means for actuating the latch, and power actuated means connected with the bails for effecting shift of the bails to the said one elevator for lifting said one elevator by the hoisting tackle.

15. Apparatus for handling stands of drill pipe in a derrick of a rotary drilling rig which includes a hoisting tackle suspended from the top of the derrick, a turntable through which the drill pipe is raised and lowered into the bore hole or removed therefrom by the hoisting tackle, said apparatus including a track having a section extending laterally of the turntable and a section for mounting on the turntable, a pair of bails, means conmeeting the bails with the hoisting tackle, a pair of elevators, one of said elevators being seatable on one of the sections of the track when the other elevator is carried by said bails, power actuated transfer means for shifting said one elevator along the track to the other section of the track, means for automatically releasing said bails upon contact of said one elevator with the track and to further lowering of the hoisting tackle, power actuated means connected with the bails for effecting shift of the hails from said one elevator to the elevator to be lifted by the hoisting tackle, and means for selectively and remotely controlling the power actuated means.

16. An apparatus for handling stands of drill pipe in a derrick of a rotary drilling rig which includes a turntable having a rotary part through which a drill pipe extends, a hoisting tackle suspended from the top of the derrick and including a traveling block, bails depending from the traveling block, a first elevator seated upon the rotary part of the turntable and engaging a shoulder of a tool joint member of the drill pipe which extends through said rotary part for supporting the drill pipe by the rotary table, a second elevator removably carried by said bails for engagement with the shoulder of a tool joint member on the upper end of a stand of drill pipe to be connected with the drill pipe supported by the turntable and for lifting said drill pipe from support by the first elevator after the connection is made, power actuated means for shifting the first elevator from off said rotary port of the turntable to accommodate the second elevator on the rotary part of the turntable, means for automatically shifting the bails from the second elevator to the first elevator to connect the first elevator with-the hoisting tackle for use in handling a succeeding stand of drill pipe to be connected with the drill pipe supported by the turntable, and means for remotely operating the power actuated means.

17. Apparatus for handling stands of drill pipe which make up the drilling string of a rotary drilling rig when the drilling string is to be run into a bore hole or removed therefrom, and which drilling rig includes a derrick having a hoisting tackle suspended from the top of the derrick and includes a traveling block for supporting the drilling string in the rotary member of a turntable at the base of the derrick, said apparatus including a bracket for attachment to the turntable laterally of the rotary part thereof, a track having a fixed section carried by the bracket and a section for mounting on the rotary part of the turntable to be rotated therewith, a pair of bails, means for connecting the bails with the traveling block to swing about a horizontal axis and to move to and from each other at their lower ends, a pair of elevators each having oppositely directed arms provided with upwardly and inwardly inclined slots to provide hooks having bail engaging seats at the ends of the slots, one of said elevators being seatable on one of the sections of the track at a time when the other elevator is carried by the bails of the traveling block, power actuated transfer means carried by said bracket and having a catch projected by the power actuated transfer means into engagement with the part of the elevator seated on the track section to shift said elevator along the track to the other section to clear the track section for support of the other elevator, safety latches on said elevators adapted to close said slots when the elevators are supported by said bails, said latches having means for engagement with the tracks to move said latches from said slots to free the bails when an elevator is seated on the tracks and further downward movement of the traveling block causes the bails to slide out of the slots and engage outer sides of the track, andmeans for effecting shift of the bails along the track and into registry with the hooks of said one elevator and in position for the bails to engage the hooks upon upward movement of the traveling block.

18; An apparatus for handling stands of drill pipe in a derrick of a rotary drilling rig which includes a turntable having a rotary part through which a drill pipe exaoeasoc,

l tends, a hoisting tackle suspended from the top of the derrick and including a traveling block, bails depending from the traveling block, a first elevator seated upon the rotary part of the turntable and engaging a shoulder of a tool joint member of the drill pipe which extends through said rotary part for supporting the drill pipe by the rotary table, a second elevator removably carried by said bails for engagement with the shoulder of a tool joint member on the upper end of a stand of drill pipe to be connected with the drill pipe supported by the turntable and for lifting said drill pipe from support by the first elevator after the connection is made, power actuated means for shifting the first elevator out of engagement with the drill pipe, means for shifting the hails from the second elevator to the first elevator whereby the first elevator may be'used for engagement with a succeeding stand of drill pipe to be connected with the drill pipe supported by the turntable, power actuated means for operating the bail shifting means, and means for remotely controlling the power actuated means. i

19. In an apparatus of the character described, an elevator, a turntable having a fixed part and apart rotatable in the fixed part, a plate member connected with the rotary .part of the turntable to rotate therewith, a track section carried by the plate member transversely of the rotary part of the turntable for supporting the elevator thereon, a radially disposed fixed track section, means for selectively stopping rotation of the plate memher with the track section thereon in registry with the radially disposed tracksection, and means for shifting the elevator from one track section to the other.

20. In an apparatus of the character described, a pair of elevators, a turntable having a fixed part and a part rotatable in the fixed part, said rotary part having a barrel portion, a master bushing in said barrel portion, a stripper carried on the master bushing for stripping drilling fluid from a drilling string, a hoist, an elevator carried by the hoist, a plate member having a portion seated upon the stripper for retaining the stripper and having a driven connection with the master bushing to rotate therewith, a track section carried transversely upon the plate member for supporting said elevator thereon to carry the drilling string independently of the hoist, a radially disposed fixed track section for carrying a second elevator, means for connecting the hoist with 4 the second elevator for removing the second elevator, means for stopping rotation of the plate member with the track section thereon in registry with the fixed track section, and power means for shifting the first elevator from the track section on said plate'member to the fixed track section.

21. In an apparatus for handling stands of drill pipe to be connected with a string of drill pipe, a pair of elevators, a turntable having a fixed part and a part rotatable in the fixed part, said rotary part having a barrel portion, a master bushing in said barrel portion, a strip per carried on the master bushing for stripping drilling fluid from. a drilling string, a plate member having a portion seated upon the stripper for retaining the stripper and having a driven connection with the master bushing to rotate therewith, a track section carried transversely upon the plate member for supporting one elevator thereon to carry the drilling string in the turntable, a hoist carrying bails for connection with said elevator to lift the drilling string to a position for disconnecting a stand of drill pipe therefrom, a radially disposed fixed track section arranged to register with the transverse track section in one position of the rotary part of the turntable, means for retaining the plate member with the track section thereon in said registering position with the radial track section, and power means for shifting a second elevator from the radial track section onto the transverse section for supporting the drilling string.

22. An apparatus for hoisting pipe in a series of raising and lowering sequences involved in the connection all) f the pipe into a string of pipe for use in a bore hole, said apparatus including a single hoist, bails suspended from said hoist, a platform member through which the pipe is lowered, dual elevators adapted to be alternately connected and disconnected with bails of said single hoist for supporting the pipe by the hoist during a raising and lowering sequence and for supporting the string of pipe on the platform member between said sequences, said bails being disconnected from and connected to the elevators upon lowering of the bails and lifting the bails respectively by means of said single hoist, guide means on the platform member for guiding the disconnected elevator thereon away from the string of pipe, and said bails having a part engageable with the guide means for facilitating shift of the bails from disconnecting position to connection with the elevator on said guide means.

23. An apparatus for hoisting pipe in a series of raising and lowering sequences involved in the connection of the pipe into a string of pipe for use in a bore hole, said apparatus including a hoist, bails suspended from the hoist, a platform member through which the pipe is lowered, dual elevators adapted to be alternately connected with hails of the hoist for supporting the pipe by the hoist during at raising and lowering sequence and for supporting the string of pipe on the platform member between said sequences, guide means on the platform member for guiding the elevators during exchange thereof, power means, a rider reciprocable on the guide means and connected with the power means, a catch on the rider and adapted to engage a part on the elevator supporting the string of pipe to complete a connection between the power means and said elevator to shift the elevator on the guide means under power, and said bails having a part engageable with the guide means for facilitating transfer of the bails from one elevator to the other.

24. An apparatus for hoisting pipe in a series of raising and lowering sequences involved in the connection of the pipe into a string of pipe for use in a bore hole, said apparatus including a hoist, bails suspended from the hoist, a platform member through which the pipe is lowered, dual elevators adapted to be alternately connected with bails of the hoist for supporting the pipe by the hoist during at raising and lowering sequence and for supporting the string of pipe on the platform member between said sequences, guide means on the platform member for guiding the elevators during exchange thereof, power means, a rider reciprocable on the guide means and connected with the power means, a catch on the rider and adapted to engage a part on the elevator supporting the string of pipe to complete connection between the power means and said elevator to shift the elevator on the guide means under power, power means for shifting the bails under power, and means for connecting and releasing the bails with said power means, said bails having a part engageable with the guide means for facilitating transfer of the bails from one elevator to the other.

25. In an apparatus of the character described, a turntable having a fixed part and a part rotatable in the fixed part, said rotary part having a barrel portion, a master bushing in said barrel portion, a stripper carried on the master bushing for stripping drilling fluid from a drilling string, a hoist, an elevator carried by the hoist and adapted to be connected with the drilling string for lifting the drilling string through the stripper, a plate memher having a portion seated upon the stripper for retaining the stripper, a second elevator, a track extending transversely of the plate member for supporting the second elevator thereon, and power means for shifting the second elevator along said track to support the drilling string.

26. An apparatus for handling stands of pipe in a derrick which includes a hoisting tackle suspended from the top of the derrick and a platform through which the pipe is raised and lowered into the bore hole or removed therefrom by the hoisting tackle, said apparatus including a track extending over the bore hole and laterally of the platform, a pair of bails connected with the hoisting tackle, a pair of elevators for engaging said stands of pipe, one of said elevators being seatable upon the track over the bore hole and the other elevator being carried by said bails, safety means on the elevators adapted for retaining the bails when an elevator is carried by the bails and having a part engageable with the track to release the safety means when an elevator is seated on said track, power actuated transfer means for shifting said one elevator along the track away from the bore hole to accommodate the other elevator when it is lowered by the hoisting tackle onto the track over the bore hole, guide means suspended in the derrick for guiding the bails, a runner on the guide means, means connecting the runner with said bails, and means connected with the lower end of the guide means for shifting the bails from one elevator to the other when both elevators are on said track.

27. An apparatus for hoisting pipe in a series of raising and lowering sequences, including a single hoisting means, dual elevators serving to support the pipe and to carry the pipe in said raising and lowering sequences respectively, power means at the base of the hoisting means for transferring the elevators to alternately support said pipe and to carry said pipe, said hoisting means having a connecting means for the elevators, and said connecting means being disconnected from the pipe supporting elevator upon lowering of the connecting means from the pipe supporting elevator and connected with the other elevator upon lifting of the connecting means by the hoisting means.

28. An apparatus for handling stands of pipe in a mast or derrick from which the pipe is lowered into or removed from a hole, including a single hoisting apparatus, an elevator connecting means carried by the single hoisting apparatus, dual elevators for alternate suspension from said connecting means, a platform surrounding said hole adapted for supporting said elevators, means for disconnecting one elevator from said connecting means and connecting the other elevator, and power means for shifting said elevators between said disconnecting and connecting position with the hoisting apparatus for alternately supporting a stand of pipe While making and breaking connections between said stands of pipe during the process of coming out of or going in the hole.

29. An apparatus for hoisting pipe in series of raising and lowering sequences, including a single hoisting means for both raising and lowering the pipe in one and the other of said series, dual elevators alternately serving to support the pipe and to carry the pipe from said single hoisting means in said raising and lowering sequences, one of said elevators being in a position to support the pipe when the other is in lateral rest position, and power means for shifting the elevators from one position to enable connection of the hoisting means with an elevator at said one position to the other position to enable disconnection of the hoisting means with the elevator at said other position depending upon whether the pipe is to be raised or lowered by the hoisting means.

30. An apparatus for hoisting pipe in a series of raising and lowering sequences as described in claim 29, and including means for controlling the power means remotely of the elevators.

31. An apparatus for hoisting pipe in a series of raising and lowering sequences involved in the connection of pipe into a string of pipe, including dual elevators, a support having seats at the respective ends thereof, one for seating an elevator for supporting the string of pipe and the other for seating an empty elevator, a hoist, bails suspended from the hoist for connection with one and the other of the elevators on said seats, power means for swinging the bails when released from one elevator on one of the seats to the elevator on the other seat to remove said other elevator by the hoist, and power means for shifting the other elevator from its seat on the support to the seat previously occupied by the elevator which was removed by the hoist.

References Cited in the tile of this patent UNITED STATES PATENTS 1,621,009 Giles Mar. 15, 1927 2,049,008 Herrick July 28, 1936 2,226,947 Sheldon Dec. 31, 1940 2,611,146 Buckley Sept. 23, 1952 2,640,681 Johnston June 2, 1953 2,747,751 Stone et a1. May 29, 1956 

